<pre>
  BIP: 102
  Layer: Consensus (hard fork)
  Title: Block size increase to 2MB
  Authors: Jeff Garzik <jgarzik@gmail.com>
  Status: Closed
  Type: Specification
  Assigned: 2015-06-23
</pre>

==Abstract==

Simple, one-time increase in total amount of transaction data permitted in a block from 1MB to 2MB.

==Motivation==

# Continue current economic policy.
# Exercise hard fork network upgrade.

==Specification==

# MAX_BLOCK_SIZE increased to 2,000,000 bytes at trigger point.
# Increase maximum block sigops by similar factor, preserving SIZE/50 formula.
# Trigger:  (1) Block time 00:00:00 on flag day, AND (2) 95% of the last 1,000 blocks have signaled support.

==Backward compatibility==

Fully validating older clients are not compatible with this change.
The first block exceeding 1,000,000 bytes will partition older clients
off the new network.

==Discussion==

In the short term, an increase is needed to continue to current
economic policies with regards to fees and block space, matching
market expectations and preventing market disruption.

In the long term, this limit should focus on reflecting the maximum
network engineering limit.

==Implementation==

https://github.com/jgarzik/bitcoin/tree/2015_2mb_blocksize

